Mounting-block for printing-plates.



land,

in Mountmg-Bloeks for Printing-Plates, oi"v mqnna'i w. nAnuisoN, or jnn'urlnonn, MARYLAND Specification 0f Letters Paten't.

MOUNTING-BLOCK FOR PRINTING-PLATES;

Patented Jan. 29, 1907.

Application filed March 24;, 1906. Serial No. 307,847-

To MM III/1111111 df: lrmtj HON/(70PM:

Be it known that I, ALBERT 'W. Illumrson, of the city-oi Baltimore and State of Maryhave invented certain Improvements which the'following is a specification.

The primary object of this invention is toprevent as far as is possible the distortion of metal printi 'ig-plates by the warping of the wood blocks to which they are secured, such distortion being due to changes in temperature and the hygroscopic condition of the air. l

A secondary object of the said invention is to counteract the nltimate ell'ect of lateral shrinkage of the wood blocks, as will-herein-' after fully appear. With the above objects in view the said invention consists in sub stituting for a mounting-block in a single piece to which the printinglate is secured a block formed of a multip icity of -lateral sections which are not connected except by means of dowelnns which )ass entirely through the said sections and old in place by friction only, the ends of the dowel-pins being ilush with the l ateral edges oi. the block. By this c mstruction .the warping of the mounting-blocks in ordinary circinnstances is practically reduced to a nullity for the rea son that the block is a flexible device whose surface will conform to that of the printingplate, the dowel-pins admitting of the movement of each section of the block independently ol' the others.

In. the further description oi the said invention which follows reference is made to the accompanying drawing, forming a part hereof and which is a ')erspe'ctive view of a printing-plate mounted upon a block con strueted in :wcordance with the present invention, a part of the prii'iting-plate being cut away to show the wood block beneath.

Referring now to the drawing, the wood moumixing-block is shown asiormed ol three sectionsc, I), and c, the grain ol" the wood extending longitudinally of the sections. The adj acent sides ol" the sections are not in absolute contact, there being minute spaces between them. These s aces are designated. but. The sections a, and c are-connected by driven dowel-pins e, which pass through all the sections, or extend from one side of the block to the other, the ends of the dowel- I pins being flush with the lateral edges of the block, and which dowel-pins, owing to the non-shrmkage in their length, represent at all times the original width of the block.

Should the block shrink in width, the dowels, not being glued or otherwise fastened to the sections thereof, will merely project slightly beyond the outer sections, and the furniture of the chase in that case will bear against them instead of the sides of the block.

From the foregoing description it will be understood that when, a printing-plate mounted upon the improved block is once locked in a chase it will not become loose by shrinkage of the wood, as the onlyehange e'll'ected by the shrinkage is the withdrawal of the outer sections of the block from the furniture of the chase.

I claim as my invention 1. A wood nu'ninting-block for a printingplate, which consists of a multiplicity oflat cral unattached sections, connected only by 'dowelpins which are driven through, Without being secured to, all the sections, the ends of the dowel-pins being flush with the lateral edges of the block, and against which the lurniture bears iiulependently of thesections in. lookingup the Form, as and for the purpose speci'lied. 1

, 2. A wood niountmg-block for a printingplate, which consists of a'multiplicity of lateral sections connected by'doweLpins which are driven through,without attachment to, all the sections, and extending from one side ol the block to the other, there being spaces between the adjacent edges of the said sections, substantially as, and for the purpose speciiied.

ALBER'I W. HARRlSON. Witnesses:

'lnoMAs G. HULL, WM. '1. HowAnD. 

